A new study revealed that the presence of smartphones, tablets or laptops in the children's bedroom may negatively affect the quantity and quality of their sleep.

It has been widely known that using smartphones or tablets at night could lead to reduced sleeping hour and poor sleep quality. However, the study published in the journal JAMA Pediatrics showed that the mere presence of these devices in the bedroom could also disrupt sleep quality and quantity in children.

"Sleep is an often undervalued but important part of children's development, with a regular lack of sleep causing a variety of health problems," said lead author Ben Carter, of King's College London, in a report from Los Angeles Times. "With the ever growing popularity of portable media devices and their use in schools as a replacement for textbooks, the problem of poor sleep among children is likely to get worse."

For the study, the researchers conducted a systematic review and meta-analysis of 467 randomized clinical trials, cohort studies and cross-sectional study designs. Of those, the researchers identified 20 cross-sectional studies, with a total of 125,198 children between ages 6 and 19, for their methodological quality.

The researchers found that 41 percent children who have their mobile devices in their bedroom during bedtime reported not enough sleeping hours. On the other hand, only 31.5 percent of the children who do not have access to their mobile devices at night reported that they didn't get enough sleep. Children who use their devices before sleeping reported have the highest percentage of reduced sleep quantity, 45.4 percent.

Furthermore, children who used or with access to their devices reported poor sleep quality, 52 percent and 44 percent respectively. About 34 percent of the children with no access of their devices at night reported similar poor sleep quality.

Although the results do not show causative relationship between device-usage and sleep quality, the researchers noted that parents should be aware if the devices of their children is keeping the kids awake at night. The digital content of the devices could psychologically stimulate children making them more awake. Furthermore, the light coming from the devices could disrupt the body's circadian rhythm.